US5049835A
Expired / Lapsed
US
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Modified cascode circuit
Assignee: Grumman Corp
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Filing: 1990-02-27
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Granted: 1991-09-17
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Expires: 2010-02-27
Abstract
Abstract Conventional cascode circuits achieve a performance which is not optimum. To enhance performance, the cascode circuit of the present invention has an input stage FET that has a saturation current which is greater than the saturation current of the output stage common gate FET. Since the maximum power of a cascode circuit is related to the maximum voltage swing at the drain of the common gate FET, when the saturation current of the common source FET is greater than that of the common gate FET, the common source FET essentially acts as a switch to turn the common gate FET fully on, without dissipating any appreciable voltage from the same, so that a maximum voltage swing may be produced at the drain of the common gate FET.
Inventors
- 👤 Carmine F. Vasile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:07
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/08; H03F1/22; H03F1/226
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
85 words
A cascode circuit comprising: a common gate FET having a saturation current; a common source FET having another saturation current connected to the common gate FEt for driving the same, the saturation current of the common source FET being greater than the saturation current of the common gate FET by a ratio of approximately between 1.5 to 2.0 to ensure that the common gate FET is adaptable to provide a maximum voltage swing at its drain to thereby enhance the performance of the cascode circuit.
Claim 2
Dependent Claim
85 words
A cascode circuit comprising: a common gate FET having a saturation current; a common source FET having another saturation current connected to the common gate FEt for driving the same, the saturation current of the common source FET being greater than the saturation current of the common gate FET by a ratio of approximately between 1.5 to 2.0 to ensure that the common gate FET is adaptable to provide a maximum voltage swing at its drain to thereby enhance the performance of the cascode circuit.
Claim 3
Dependent Claim
60 words
The cascode circuit according to claim 1 wherein the common gate FET and the common source FET are fabricated on the same substrate to include respective source, drain and gate regions, the ratio of the saturation current between the respective FETs being effected by varying the distances between the source and drain regions of the respective FETs in the substrate.
Claim 4
Dependent Claim
72 words
A cascode circuit comprising: an output stage including a common gate FET having a saturation current; an input stage having at least two common source FETs connected in parallel, and having a combined saturation current greater than that of the common gate FET; wherein the connected in parallel common source FETs effectively provide the common gate FET with maximum voltage swing at its drain to enhance the performance of the cascode circuit.
Claim 5
Dependent Claim
72 words
A cascode circuit comprising: an output stage including a common gate FET having a saturation current; an input stage having at least two common source FETs connected in parallel, and having a combined saturation current greater than that of the common gate FET; wherein the connected in parallel common source FETs effectively provide the common gate FET with maximum voltage swing at its drain to enhance the performance of the cascode circuit.
Claim 6
Dependent Claim
37 words
The cascode circuit according to claim 3, wherein the saturation current of the combined common source FETs is greater than the saturation current of the common gate FET by a ratio of approximately between 1.5 to 2.0.
Claim 7
Dependent Claim
23 words
The cascode circuit according to claim 3, wherein the common gate FET and the common source FETs have substantially identical current voltage characteristics.
Claim 8
Dependent Claim
22 words
The cascode circuit according to claim 3, wherein the common gate FET and the common source FETs have different current voltage characteristics.
Claim 9
Dependent Claim
98 words
A cascode circuit comprising: an output transistor having a first saturation current; at least one driver transistor having a second saturation current connected to the output transistor, the saturation current of the driver transistor being greater than the saturation current of the output transistor by a ratio of approximately 1.5 to 2.0 such that no appreciable voltage from the output transistor is dissipated by the driver transistor as the output transistor reaches it saturation current, to thereby enhance the output of the cascode circuit by enabling the output transistor to effect a maximum voltage swing at its output.
Claim 10
Dependent Claim
98 words
A cascode circuit comprising: an output transistor having a first saturation current; at least one driver transistor having a second saturation current connected to the output transistor, the saturation current of the driver transistor being greater than the saturation current of the output transistor by a ratio of approximately 1.5 to 2.0 such that no appreciable voltage from the output transistor is dissipated by the driver transistor as the output transistor reaches it saturation current, to thereby enhance the output of the cascode circuit by enabling the output transistor to effect a maximum voltage swing at its output.
Claim 11
Dependent Claim
20 words
The cascode circuit according to claim 7, wherein the output and driver transistors are common gate and source FETS, respectively.
Claim 12
Dependent Claim
25 words
The cascode circuit according to claim 7, wherein the output transistor is a common base transistor and the driver transistor is a common emitter transistor.
Claim 13
Dependent Claim
85 words
A cascode circuit comprising: an output stage including a transistor having a saturation current; an input stage having at least two transistors connected in parallel, the two input stage transistors being substantially identical to the output stage transistor and having a combined saturation current greater than that of the output stage transistor; wherein the connected in parallel input stage transistors effectively ensure that a maximum voltage swing is provided at the output of the output stage transistor for improving the performance of the cascode circuit.
Claim 14
Dependent Claim
85 words
A cascode circuit comprising: an output stage including a transistor having a saturation current; an input stage having at least two transistors connected in parallel, the two input stage transistors being substantially identical to the output stage transistor and having a combined saturation current greater than that of the output stage transistor; wherein the connected in parallel input stage transistors effectively ensure that a maximum voltage swing is provided at the output of the output stage transistor for improving the performance of the cascode circuit.
Claim 15
Dependent Claim
23 words
The cascode circuit according to claim 10, wherein the output stage and input stage transistors are common gate and common source FETs, respectively.
Claim 16
Dependent Claim
34 words
The cascode circuit according to claim 10, wherein the combined saturation current of the input stage is greater than the saturation current of the output stage by a ratio of approximately 1.5 to 2.0.
Claim 17
Dependent Claim
28 words
The cascode circuit according to claim 10, wherein the output stage transistor is grounded at its base and the input stage transistors are grounded at their common emitter.
References Cited (Backward Citations)
No citation records indexed.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |